An area containing recoverable deposits of oil. For every barrel of oil recovered, two remain unrecoverable. Existing oil wells are yielding ever-declining production rates. Oil and gas resources are finite and non-renewable. The challenge is not in discovering oil, but in recovering it. Eighty percent of the world's total recoverable oil has been discovered. We will eventually discover the remaining 20 percent. The remaining 20 percent is under Arctic ice and deep waters and, therefore, is more difficult to discover and recover. Yet, many people are not aware that the world has been projected to run out of petroleum before the end of the 21st century. We take petroleum for granted, but when we run out of oil and gas, all automobiles, aircraft and ships will be grounded. If we maintain the status quo in this area, there will be no light.

a region rich in petroleum deposits (especially one with producing oil wells)

an area with an abundance of oil wells extracting petroleum (oil) from below ground